Report any XLogReadRecord() error in XlogReadTwoPhaseData().

Buildfarm members kittiwake and tadarida have witnessed errors at this
site.  The site discarded key facts.  Back-patch to v10 (all supported
versions).

Reviewed by Michael Paquier and Tom Lane.

Discussion: https://postgr.es/m/20211107013157.GB790288@rfd.leadboat.com

diff --git a/src/backend/access/transam/twophase.c b/src/backend/access/transam/twophase.c
index bc518c88672e7d461a41423db9ec53f8d2f8211c..4aa382839e9d957aa96d146ca5ffc69b418083f2 100644 (file)
--- a/src/backend/access/transam/twophase.c
+++ b/src/backend/access/transam/twophase.c
@@ -1409,10 +1409,18 @@ XlogReadTwoPhaseData(XLogRecPtr lsn, char **buf, int *len)
    ThisTimeLineID = save_currtli;
 
    if (record == NULL)
-       ereport(ERROR,
-               (errcode_for_file_access(),
-                errmsg("could not read two-phase state from WAL at %X/%X",
-                       LSN_FORMAT_ARGS(lsn))));
+   {
+       if (errormsg)
+           ereport(ERROR,
+                   (errcode_for_file_access(),
+                    errmsg("could not read two-phase state from WAL at %X/%X: %s",
+                           LSN_FORMAT_ARGS(lsn), errormsg)));
+       else
+           ereport(ERROR,
+                   (errcode_for_file_access(),
+                    errmsg("could not read two-phase state from WAL at %X/%X",
+                           LSN_FORMAT_ARGS(lsn))));
+   }
 
    if (XLogRecGetRmid(xlogreader) != RM_XACT_ID ||
        (XLogRecGetInfo(xlogreader) & XLOG_XACT_OPMASK) != XLOG_XACT_PREPARE)